Manufacture of oxidized petroleum acid compounds



g- 8, 1939 R. E. BURK I 2,168,699

MANUFACTURE OF OXIDIZBD PETROLEUM ACID COMPOUNDS Filed Dec. 12, 1936 [/0I /60 A 200 220 240 260 250 J00 J20 J40 J J60 A620 Mawer 0% wyfi, per 671 N VENTOR.

AT'TORNEYJ,

Patented Aug. 8, 1939 PATENT. OFFICE MANUFACTURE OF OXIDIZED PETBOLEACID COMPOUNDS Robert E. Burk, Cleveland, Ohio, minor to The StandardOil Company, Cleveland, Ohio, a corporation of Ohio Application December12, 1936, Serial No. 115,648

5 Claims.

for many desired usages it has been impracticable to effect a separationto such an extent as to permit commercial adaptability to certainspecific usages. The conglomerate mixture product has had to be employedpractically as an indiscrimi nate mixture, and with its consequentlimited capabilities of usage. In accordance with the present inventionhowever, carbon acids of selectively desired character may be made frompetroleum hydrocarbons, and such as to have applicability to purposesinvolving exacting requirements.

To the accomplishment of the foregoing and related ends, the invention,then, comprises the features hereinafter fully described, .andparticularly pointed out in the claims, the following description andthe annexed drawing setting forth in detail certain illustrativeembodiments of the invention, these being indicative however, of but afew of the various ways in which the principle of the invention may beemployed.

In said annexed drawing the sole figure is a graph illustrating therelation of stocks to products.

Instead of starting with very high molecular hydrocarbons and dependingupon more or less breaking down to attain lower molecular products, thepresent invention selects hydrocarbon raw material in view of thecharacteristics of the product which it is desired to make. Thus, for agiven desired acid number product, hydrocarbon or petroleum raw materialis taken, and there being a definite relation establishable between acidnumber (determined as milligrams per gram of sample) in the productdesired, with relation to the molecular weight or carbon atoms of theacid, correspondingly, the hydrocarbon raw material is selected by itsboiling point. Closely cut distillate fractions of petroleum 7 can thusbe taken, and with corresponding carbon atom composition, and by theavoidance of molecular breakdown, because of the low conversion rate perpass and the closely controlled operations characteristic of theinvention, the desired properties may be attained in the product.Petroleums of different source may be employed, depending upon theproducts desired, for most practical applications, acid products of acidnumber -300. A close out liquid petroleum fraction corresponding to theselected acid number desired in such range is thus taken as rawmaterial. The selected raw material is initially brought up. to reactiontemperature range by heating, and 5 then oxygen or more commonly, air,is blown into the liquid under controlled conditions. The initialtemperature'depends somewhat upon the particular hydrocarbon beingtreated, whether of low or higher molecular'weight and boiling point, 10but it must be low enough to avoid heating to excessive vaporizationunder the pressure conditions prevailing. Generally the pressure may be1 about sixty to one hundred pounds per square inch, and the temperatureabout 300-330 F. In ll the oxidational process, exothermic in character,heat isgenerated, and in the operation of the present process control ofthe temperature is carefully maintained, the reaction vessel desirablyhaving a temperature control jacket or coils go for such purpose, andthe temperature is maintained in a desired reaction range, Vapors whichform are caught by suitable condensing means, and-condensed water isseparated out, and condensed oil is returned to the reaction masa;Desirably, fresh feed hydrocarbon distillate is introduced into thereaction mass continuously; Preferably at the lower portion, and with anacid number attained andthence continuously maintained at a desired ratein the reaction mass, as u for instance an acid number of from 25, andbest 10-20, liquid is drawn off, preferably at the upper portion, andpreferably also continuously. The air introduced into the reactinghydrocarbon liquid may be at some convenient operating presu sure, up toseveral hundred pounds or more, desirably for instance 78-100 lbs. persq. in., and is disseminated thoroughly into the liquid by suitabledividing means to effect a good distribution and action. The air feedrate is desirably from a about 2 to-about 100 cu. ft. per hour per gal.of oil being reacted, and preferably not over 40 cu. ft. per gal, perhour.

The liquid withdrawn from the reaction zone is mixed with an alkalimetal neutralizant, de- 4 sirably a caustic soda or sodium carbonatesolution, as for instance 0.5-5 N. for caustic soda, or 0.5 to saturatedat room temperature for sodium carbonate. After thorough mixing andsettling, the acid product may be set free from the alkali g. metal saltso formed, if desired; or a selective fractional precipitation maybecarried out by successive precipitations with heavy metal ions, as byadditions of manganese, cobalt, iron or the like, chlorides, hydroxides,etc.

Desirably, a catalyst may be added to the hydrocarbon liquid initially;With an accumulation of produced acid in the reaction zone a catalyticeifect therefrom however ultimately is available. As a catalyst,manganese naphthenate or stearate is advantageous. The amount may be0.2-0.8 or more, and desirably about 0.4 per cent. Similar other highmolecular compounds of manganese. cobalt, etc. may be employed,

As anillustrative example: For a product of acid number 265,- apetroleum distillate fraction of 300 to 310' F. I. B. P. 370 to 390 F.F. B. P. is heated to about 305 F. to 320 F. and air is blown thereinat, e. g., 80 lbs. pressure and about 20 cu. ft. per hour per gal, inthe reaction vessel in the presence of about 0.4 per cent of manganesestearate. The temperature is controlled at about 320 1"., and when theacid number in the reaction zone samples at. about 20, fresh feed isstarted at the bottom and the drawofl from the upper portion. The drawnoil liquid is mixed with, e. g., 2.5 N. caustic soda solution. Aftersettling, the pH is adjusted to barely acid and heavy metal salts areprecipitated in successive fractions by separate precipitating additionsof, e. g., lead nitrate. The thus selectively separated products areavailable for application to usages where a particularly definitematerial is desired. Of course, where such close splitting down is notdesired, the products may be employed directly, without the fractionalprecipitation separation.

Or. the acid may be freed from the sodium salt solution, e. g., byadding just enough sulphuric acid. The thus freed acids may be subjectedto fractional distillation.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the following claims, or the equivalent ofsuch, be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a process of making an oxidized petroleum acid compound, heatingto about 305' 1". a petroleum fraction of 300-390 I". B. P blowing airtherein at about 80 lbs. pressure and about 20 cu. ft. per hour pergal., controlling the temperature at 310-330 F., and maintaining theacid number in the reaction mass at not exceeding about 25, whilecontinuously introducing fresh petroleum below and drawing on liquid 8.CW0.

2. In a process of making an oxidized petroleum acid compound, heating apetroleum fraction of 300-390 F. B. P., blowing air therein at about 80lbs. pressure and about 20 cu. ft. per hour per gal., while controllingthe temperature at 300-330 F., maintaining the acid number in thereaction mass at 25, and drawing liquid.

3. In a process of making an oxidized petro leum acid compound, heatingto about 305 1'. a petroleum fraction of 300-390" F. B. P., blowing airtherein at about 80 lbs. pressure and about 20 cu. ft. per hour pergal., controlling the temperature at 300-330 F., maintaining the acidnumber in the'reaction mass at not exceeding about 25, and drawing oil!liquid.

4. In a process of making an oxidized petroleum acid compound, heating apetroleum fraction of 300-390 F. B. P., blowing air therein at about 20cu. ft. per hour per gal., while controlling the temperature at 300-330E, and maintaining the acid number in the reaction mass at 5 to 25, anddrawing of! liquid.

5. In a process of making an oxidized petroleum acid compound, selectinga liquid petroleum material of boiling point chosen by reference to thecarbon atom content of the acid product ultimately desired, heating suchpetroleum ma- ROBERT E. BURK.

